The present invention relates to eye glasses for experimentation and testing which are mainly utilized for measuring the refraction on one or both eyes of a patient.
Eye glasses for testing of the known type comprise screw-operated devices for the adjustment to the distance between the pupils and the adjustment in height, and they allow also the rotation of test lenses in their seats for determining the axes of astigmatism.
These eye glasses are adapted for adjustment to the head of the patient with the aid of a bridge and adjustable lenses as well as adjustable support means on the nose of the patient. The lense are adjustable by sliding on the bridge, with the sidepieces of the eye glasses either being pivoted at the bridge or on the frame holding the lenses. The support means for the nose are adjustably mounted either on the lens frame or at the transverse axis forming the bridge, and in certain modifications the bridge itself is formed of elements which are adjustable relative to each other either by telescoping or by sliding.
The test eye glasses presently used have several drawbacks, among which are: the fact that they are not at all esthetic, which discourages patients from wearing them for a lengthy test period; the manufacturing cost is high; the near-impossibility of testing multifocal or progressive lenses or lenses to be worn with eye glasses which the patient is already wearing.